Jester
Full Member level 6
I seem to recall that UL 506 approved transformers must have an embedded thermal cut out. Is that correct?
Let's say I have a small 20VA PCB mount transformer powered from 120V. The device that the transformer is installed in has a 120V, 20A source, and is fused internally with a 5A fuse. Under normal conditions the transformer draws less than 200mA, so if the transformer was overloaded it could draw (in theory) 5A continuously and over heat if there was no thermal cut out.
Let's say I have a small 20VA PCB mount transformer powered from 120V. The device that the transformer is installed in has a 120V, 20A source, and is fused internally with a 5A fuse. Under normal conditions the transformer draws less than 200mA, so if the transformer was overloaded it could draw (in theory) 5A continuously and over heat if there was no thermal cut out.